The present invention is directed to bicycles and, more particularly, to various features of a bicycle sprocket apparatus.
Bicycle transmissions usually comprise either internally mounted transmissions or externally mounted transmissions. Internally mounted transmissions usually have a planetary gear mechanism built into a rotating hub (e.g., one of the bicycle wheels), and a chain is used to drive a sprocket coupled to the planetary gear mechanism. A clutch mechanism is coupled to the planetary gear transmission to select a desired speed step, and the rider operates a shift control device to control the clutch mechanism. Externally mounted transmissions usually have a derailleur for switching a chain among a plurality of external sprockets, and the rider operates a shift control device to control the derailleur. Some applications combine the features of internally mounted transmissions and externally mounted transmissions by coupling a plurality of sprockets to the hub-mounted planetary gear mechanism and by using a derailleur to shift the chain among the plurality of sprockets. Such an arrangement multiplies the number of available speed steps. A shift control device operated by the rider is used to control the clutch mechanism and the derailleur. In any event, it is always desirable to mount the one or more sprockets in an advantageous manner.